In wireless communication networks, there are communication nodes, for example microwave link nodes. Microwave link nodes normally comprise microwave link antenna devices that may be in the form of high gain antennas for high frequency applications. Such high gain antennas can be implemented by means of a variety of technical solutions such as parabolic dish antennas, horn antennas, dielectric lens antennas or flat panel array antennas.
General problems for high gain antennas at high frequencies are losses, front to back ratio and undesired lobe form, in particular excessive side lobe levels.
High gain antennas are often associated with narrow main lobes, i.e., they have small half-power beam-widths. A narrow main lobe focuses transmitted and received power and thus increases antenna gain. Half-power beam-width of most directional antennas is inversely proportional to both reflector area and carrier frequency. Thus, the higher the carrier frequency becomes, the narrower the main lobe becomes, and the larger the antenna gain becomes. Consequently, for a fixed antenna gain, reflector size can be decreased with increasing carrier frequency.
The smaller an antenna becomes, the more precision is required at manufacturing since the tolerances decrease correspondingly. Thus, high gain directional antennas become more difficult to manufacture with increasing carrier frequency/center frequency, since they are often much smaller in size than high gain antennas for lower carrier frequencies.
There is thus a need for a high gain antenna for use at high carrier frequencies having relatively low losses and desired lobe shapes, and which is less complicated to manufacture compared to prior art.